1. Field of the Invention
The invention relates to a network system for transporting audio signals among a plurality of nodes.
2. Description of the Related Art
Recently, proposed network systems configured to be able to transport audio signals in real time among a plurality of devices include, for example, those described in the following Documents 1 to 3.
In the network systems described in the Documents 1 to 3, a frame is periodically circulated along a ring transmission route formed by processors constituting the system and each of the processors reads necessary data from the frame and writes necessary data into the frame, whereby not only the audio signals but also control signals such as the Ethernet (registered trademark) frame and the like can be stably transported from any processor to any processor both of which constitute the system. The processors are connected to form a loop and then operate in a suitable mode, whereby when a communication failure occurs at one location in the network, the network can continue the transport of the audio signals and the control signals in a substantially similar manner to that before the occurrence of the communication failure and provide stable data transport in this point of view.
Aside from these systems, the network system as described in the Document 4 is also proposed.
The network system described in the Document 4 is configured such that a plurality of sub-networks are connected to one another via a connecting network to enable routings of signals from a processor belonging to one sub-network to a processor belonging to another sub-network. The routing enables the processor belonging to the one sub-network to utilize the function of the processor belonging to the another sub-network, so that even when the number of processors connectable to the one sub-network is limited depending on the maximum number of transmission channels for the audio signals determined from the standard of the network, each processor can utilize the functions of the processors exceeding the limit in the maximum number of transmission channels.
Document 1: Japanese Patent Laid-open Publication No. 2009-94589
Document 2: Japanese Patent Laid-open Publication No. 2008-99264
Document 3: Japanese Patent Laid-open Publication No. 2007-259347
Document 4: Japanese Patent Laid-open Publication No. 2007-258966